Serpent Mound State Memorial

Serpent Mound, located in Adams County, stretches about a quarter mile in length and is the largest effigy earthwork (representation of an image) known to this day anywhere in the world. While it is called Serpent Mound, it is entirely speculation that the image represents a snake with an egg in its mouth. That is how early explorers described the site and the name has stuck.

Serpent Mound is located in Ohio, east of Cincinnati, off of highway 73 and southwest of Hillsboro. It is on top of a ridge that over looks the Ohio Brush Creek. It is located in the Serpent Mound State Memorial and is accessible to the public.

Excavations of Serpent Mound found some pottery fragments, ashes, burnt stone, and some animal bones, but no human remains. According to what early archeologists found when they excavated portions of the mound, the topsoil was first removed before a layer of large stones was placed carried up from Ohio Brush Creek. Then clay was placed over and around the stones which had been dug up not far from the earthwork and carried to complete the earthwork. These early excavations also showed a thick top layer of organic matter that would have been deposited over the centuries. Some radio carbon testing indicated that it may be as old as 321 - 41 BCE make it much older than originally thought and as such it was probably constructed by members of the Adenua Culture. The new findings are the result of an indept look at the mound using geodetic survey, LiDAR analyses, hand coring, GeoProbe coring, magnetic gradiometer survey, electrical resistivity survey, ground penetrating radar, and limited excavation of a previously undocumented feature at the neck of the effigy. This new research has shed new light on the actual date of construction which had been thought to be only about 1000 years old. The descrepancy may in large part be because of the first archeological exploration of the site.

In the late 1800s, Serpent Mound had been saved from destruction when Frederic Putnam of Harvard University and the ladies of Boston purchased the site.? After this purchase, Putnam partially restored the effigy and created the Serpent Mound Park. During the course of his work, Putnam cut several exploratory trenches through the effigy. Mostly, however, what Putnam did was restore the effigy to its presumed original height by placing dirt that had washed down from the mound and accumulated along its edges,. This was the extent of exploration of the earthwork until the 1990s.

In 1991, Robert V. Fletcher conducted a more thorough study of the earthwork. located and opened one of Putnam's back-filled trenches, expanded the lateral extent of that trench into a non-Putnam back-filled section of the effigy, and from that area, secured charcoal for two radiocarbon samples. A third sample was recovered earlier by hand coring. The dates from these radiocarbon dates differ drastically from the most recent testing. Why the difference?

According to the most recent research, the difference in dating can be explained. The most likely explaination was that the site was originally constructed as early as 321 BCE by members of the Adena Culture. It then may have been later modified or remodeled to meet the needs of perhaps the Fort Ancient Culture. There may have also been some soil erosion at the exact location where samples were taken, that may have later been filled in either by nature or man thus giving an eroneous time stamp. The most recent sampling included some 18 core samples taken from various parts of the earthwork to help insure a more uniform sampling.

This most recent study will help identify when the earthworks were created. In so doing, archeologists might develop a better idea of the purpose, or meaning of the earthwork.

Besides the well-known earthwork, there are also several burial mounds found nearby. These burial mounds were most likely Adena burial mounds.

There are several burial mounds around the Serpent Mound that did contain remains. At the park, there is an interpretation center that gives visitors an overview of information known about these prehistoric cultures.

Serpent's "Tail"

Description of Serpent Mound

The head of the serpent rests on a rocky platform, which presents a precipitous face to the west, towards Brush Creek which is about 100' below the steep cliff that surrounds 3 sides of the precipice where the mound was constructed. The jaws of the serpent's mouth are widely extended as if it was in the act of trying to swallow an egg. When the first surveyors arrived at the site, there was a small pile of stones at the center of the oval which had been burned. The egg is represented by an oval enclosure about 100' long. There were also observed to elevated triangular shaped platforms on either side of what is called the serpent's mouth, but these have mostly disappeared since being recorded in the mid 1800s. This enclosure, as well as the body of the serpent, consists of a ridge of fine earth as determined by excavations and is about 4' high and from 10' - 15' wide.

It has also been suggested that the large oval at the head of the snake is not an egg, but represents the eye of the serpent as viewed from the side. Whether it is an eye or an egg will never be known for certain. An early minister who saw the serpent declared that this area must be the Garden of Eden and the snake represented the serpent tempting Eve with an apple in its mouth from the Tree of Life.

The body of the serpent winds gracefully back towards higher land, making 4 large folds before reaching the tail. The tail tapers gracefully, and is twisted up into 3 complete coils. The whole length of the mound from the end of the egg on the precipice to the last coil of the tail on the higher land is upwards of 1300' or a quarter of a mile.

Description of the earthwork as that of a serpent is controversial. Squier and Davis were among the first to survey the mound in 1848. According to the first surveyors of the area, the shape looked like a serpent with it's mouth open, about to devour an egg and this description gave way to its name we use today. Others have said that it represented the myth of the horned serpent common to many Indian cultures. Ancestors of Indians who lived around Lake Superior said that in their lore, they had removed copper from the horns of the serpent. Could the iconic earthwork represent a map that depicted a water-route back to some large body of water? No one can know for certain.

The Serpent mound is the largest effigy mound in the world. While there are several burial mounds around the Serpent mound site, the so called Serpent itself does not contain any human remains and doesn't appear to have been constructed for burial purposes. What the earthen structure was built for remains a mystery and it is only contemporary interpretations that explain the earthen structure to be a representation of a serpent. My personal feelings is that it represents the Mississippi River that goes from its headwaters south to where the river empties into the Gulf of Mexico all of which may be a symbolic representation used to explain to future generations where they originated. That seems more plausible than it is a giant snake trying to swallow an egg. Besides, Ohio was awash with rattlesnakes when the first settlers came.

Visiting the Serpent Mound State Memorial

Hours vary by season and days of the week. Please consult the Ohio Historical web site for additional information and hours.

Serpent Mound was recognized as a National Historic Landmark in 1964. Serpent Mound State Memorial is located about 20 miles southeast of Hillsboro in Adams County.